Supply Shortages Spark New Concerns as the FDA Receives Record Numbers of In Vitro Diagnostic EUA Applications

Developers Bring Concerns Over Shortages in Reagents and Swabs to Light, but Pooling Is Not Always the Answer

July 9, 2020
On July 1, 2020, the FDA held its weekly town hall-style meeting where the in vitro diagnostics (IVD) community was invited to ask clarifying questions about the guidance on IVD testing last updated on May 4, 2020, allowing emergency use authorization (EUA) for qualifying diagnostic tests for SARS-CoV-2.

The key takeaways are listed below:

  • Due to shortages in reagents, attention is turning to sample pooling. The FDA has not authorized a sample pooling scheme yet, but the agency is interested in EUA submissions for authorization. Nonetheless, some laboratories are considering implementations of sample pooling. The FDA cautions that pooling schemes in populations with a greater than 20% prevalence rate will lead to inaccurate results. Sample pooling in populations with less than a 20% prevalence rate are still prone to producing more false negatives and for that reason, any negatives obtained should be deemed “presumed negatives.” A pooling scheme that has worked historically is to take two swabs per patient and store the second swab for testing individually after confirmation that one of the pooled samples is positive, but due to the intermittent shortages in swabs, this approach may not serve useful.

  • A spike in MedWatch complaints has alerted the FDA that a popular platform’s reagent kit is producing false positive results at a rate of up to 3%. The FDA is working with the developer to rectify the situation and advised during the town hall that all positive results designated by that system be deemed “presumed positive.”

  • Developers are finding that customers are unwilling to buy tests that have not been authorized, even if they are on the notification list. Despite doubling their staff of reviewers, the FDA is still grappling with the number of applications they are seeing. Developers should consider this in their product development timeline. Keep in mind that submission of an EUA or pre-EUA is not the same as using the notification pathway. Developers would have to submit a separate notification letter to be included on the notification list on the FAQ website while awaiting EUA review.

  • Developers interested in adding a new specimen type via an EUA modification can do so, but the FDA does not recommend the use of a bridging study as effective validation. Developers should reference the EUA guidance and available templates for validation recommendations.


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The FDA held town hall-style meetings for the in vitro diagnostics community can ask questions to clarify the FDA's recently issued guidance for developing diagnostic tests for SAR-CoV-2. To read more on the key takeaways from each meeting and how Exponent can help, please see the links below:

June 1, 2020 - Accuracy Issues Still Plague Developers While FDA Looks to At-Home Testing

June 1, 2020 - FDA Publishes List of Developers Who Can No Longer Legally Market Their COVID Test

May 18, 2020 - FDA Focusing on Accuracy for In Vitro Diagnostics for COVID-19

May 5, 2020 - FDA Holds Third Town Hall Meeting to Clarify Emergency COVID-19 Diagnostics Development Guidance

April 30, 2020 - FDA Discusses First Authorized Home Collection Kit

April 17, 2020 - FDA Holds Second Town Hall Meeting to Clarify Emergency COVID-19 Diagnostics Development Guidance

April 13, 2020 - FDA Holds Town Meetings to Clarify Recent COVID-19 Diagnostics Development Guidance

April 13, 2020 - FDA Releases Updated Guidance on Diagnostics Testing as Response to COVID-19 Crisis

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